A Novel SLA for Time-DifferentiatedResilience with Efficient Resource Sharing in WDM Networks

Abstract—Internet customers may have strict resilience requirements for specific periods of times. However, these time-differentiated resilience requirements are not effectively addressed by current SLA frameworks. To satisfy the resilience-sensitive periods, a generic SLA framework typically provides upgraded protection over the entire service duration, which is unnecessary and expensive. In this study, we propose a novel SLA framework, which allows customers to specify Critical Windows (CW) to address time-differentiated resilience demands. CWs correspond to the periods that require extra protection, and are backed up using path-level pre-cross-connected protection. Considering the complementary profiles of CWs, we identify the opportunity for backup resource sharing in the time domain. To exploit backup sharing, a heuristic scheme is proposed (Globally-CW-Aware connection assignment) to reduce backup resources. Our study shows that, using the proposed SLA framework: 1) low operational complexity can be achieved; 2) backup resources can be significantly reduced; and 3) high resilience (Service Level) can be achieved for CWs.